Hamilton was a well-known dandy of his day. An obituary notice states that "timidity and variableness of temperament prevented his rendering much service to, or being much relied on by his party ... With a great predisposition to over-estimate the importance of ancient birth ... he well deserved to be considered the proudest man in England." He also supported Napoleon and commissioned the painting The Emperor Napoleon in His Study at the Tuileries by Jacques-Louis David.

Lord Lamington, in The Days of the Dandies, wrote of him that 'never was such a magnifico as the 10th Duke, the Ambassador to the Empress Catherine; when I knew him he was very old, but held himself straight as any grenadier. He was always dressed in a military laced undress coat, tights and Hessian boots, &c'. Lady Stafford in letters to her son mentioned 'his great Coat, long Queue, and Fingers cover'd with gold Rings', and his foreign appearance. According to another obituary, this time in Gentleman's Magazine he had 'an intense family pride'.

Hamilton had a strong interest in Ancient Egyptianmummies, and was so impressed with the work of mummy expert Thomas Pettigrew that he arranged for Pettigrew to mummify him after his death. He died on 18 August 1852 at age 84 at 12 Portman Square, London, England and was buried on 4 September 1852 at Hamilton Palace, Hamilton, Scotland. In accordance with his wishes, Hamilton's body was mummified after his death and placed in a sarcophagus of the Ptolemaic period that he had originally acquired in Paris in 1836 ostensibly for the British Museum. At the same time he had acquired the sarcophagus of Pabasa, an important noblemen which is now in the Kelvingrove Museum. In 1842 Hamilton had begun construction of the Hamilton Mausoleum as repository for the overcrowded family vault at the Palace. He was interred there with other Dukes of Hamilton, from the 1858 completion of the Mausoleum until 1921 when subsidence and the subsequent demolition of the Palace forced removal of the bodies to the Bent cemetery in Hamilton, where he still lies buried in his sarcophagus.[3][4]

His collection of paintings, objects, books and manuscripts was sold for £397,562 in July 1882. The manuscripts were purchased by the German government for £80,000. Some were repurchased by the British government and are now in the British Museum.